摘要 |
An internally nucleated, toughened cordierite glass-ceramic is disclosed. The cordierite glass-ceramic has good oxidation resistance and fracture toughness and coefficient of thermal expansion rivaling that of silicon nitride. The glass-ceramic may be cast as a liquid. Annealing produces a material of high crystallinity combining high hardness, high Young's modulus, good thermal stability, high strength, low density and good dielectric properties. The glass-ceramic comprises interlocking crystalline phases dominated by cordierite and a second phase having an elongated or acicular structure. A third phase may comprise a crystalline ceramic that promotes acicularity of the second phase. The third phase is preferably capable of twinning.
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